Section 1


What do you think?
You can protect yourself from serious injury during an accident if you wear all safety equipment available to you and you maintain a speed that is reasonable to your situation.

Investigate Section 1
1.
Safety features
Means of protection
Pre-1960 cars
(yes/no)
New Cars
(1,2,3)
seat belt
keeps the person in seat
and not allowing movement (inside of car)
no
1
head restraints
allow the back of the seat and headrest to
move back and forward, lowers the number
of whiplash injuries
no
1
front airbags
when a crash occurs, the air bag
pops up to prevent one from a serious
injury of banging into the car
no
1
back up sensing system
sensor in the rear sensing when the vehicle
gets too close to another object, warning
the driver
no
3
front crumple zones
created to crumple in predetermined patterns
to absorb energy of crash; front of car
no
2
rear crumple zones
(see above) but for the rear of the car
no
2
side-impact beams in doors
deflect the force of a side-impact collision
away from the head area to the legs, resisting
side penetration
no
2
shoulder belts for all seats
keeps passenger in seat during collision
no
1
anti-lock braking systems (ABS)
eliminate the need to pump brakes when
having to stop short, preventing skidding
no
2
tempered shatterproof glass
help prevent cuts
yes
1
side airbags
protects head and torso
no
2
turn signals
warn drivers of next turn
yes
1
electronic stability control
help resist rollovers
no
2/3
energy-absorbing collapsible steering column
prevents chest trauma
no
1

2.
a) 10, no many of the questions were trivia and not particularly important.

Section 2

What do you think?

I would put a roll cage and a 5 point seat belt.

Investigate X2: Newton's FIrst Law and Seatbelts


Objectives:
  • What happens to a passenger involved in a car accident without and with a seatbelt?
  • What factors affect the passenger’s safety after a collision?
  • How would a seat belt for a race car be different from one available on a regular car?


Hypothesis: Respond to each of the above objectives fully.
If a person gets into an accident without a seatbelt, they will fly through the windshield because the car is moving at a certain speed and when stopped, a human will keep traveling until stopped by an unbalanced force. How fast the vehicle was moving the amount of objects and what materials the objects are made of. A seatbelt on a race car would have more safety features included into the design than a regular car.

Materials: List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).

Procedure:
  1. Make a clay figure and then place the figure in the cart.
  2. Arrange a ramp so that the endstop is at the bottom of the ramp.
  3. Adjust the height of the ramp to make a very shallow incline.
  4. Send the cart down the ramp.
  5. Very gradually increase the height of the ramp until significant “injury” happens to your figure. Make a note of this height.
  6. Fix your clay figure. Create a seatbelt for the figure and take a "Before" picture and post in your data table.
  7. Send your cart and passenger down the ramp at the same height as in Step 5. Be sure to record your observations specifically and carefully. Take an "After" picture and post in your data table to supplement your written observations.
  8. Repeat Steps 6 and 7, using different types of material for the seatbelt.

Data and observations:
Injury Height with no seatbelt: _ m


Type of Seatbelt
Before Picture
After Picture
Description and Observations
Group
Thread




Wire




String




Yarn


The little clay man was sent flying down the incline, and crashed into the end, without significant injury. No cuts could be seen from the force of the yarn on the man and no body parts were missing or out of place. The cart hit the end of the track and the little clay man did not move sitting in place where I had placed him on the cart.

Ribbon




1-in masking






*Read the Physics Talk p268 - 271 before answering the following questions. *
Questions:
  1. Define the terms: inertia, force and pressure.
  2. In the collision, the car stops abruptly. What happens to the “passenger”?
  3. What parts of your passenger were in greatest danger (most damaged)?
  4. What does Newton’s first law have to do with this?
  5. What materials were most effective as seatbelts? Why?
  6. Use Newton's first law of motion to describe the three collisions.
  7. Why does a broad band of material work better as a seatbelt than a narrow wire?


Conclusion:
· Using Newton's First law of Motion, explain why a seat belt is an important safety feature in a vehicle. What factors affect the effectiveness of a seatbelt? What would you need to consider when designing a seatbelt for a race car? Use specific observations from this investigation to support your answers to these questions.
· Explain at least 1 cause of experimental error. Be sure you describe a specific reason.
· How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?)

USE THE RUBRIC TO MAKE SURE YOU HAVE INCLUDED ALL REQUIREMENTS!

Investigate X3: Energy and Air Bags


Objective:
  • How does an air bag protect you during an accident?

Hypothesis: Respond to the objective fully.
It acts as an unbalanced force to stop you from going to far forward during a collision.
Materials: List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).
Bag
EggProcedure:

Note: You may want to use the available technology to take "Before" and "After" pics to post in your data table to assist and elaborate on your written descriptions.

1. Measure the length of your egg #1. Measure the mass of your egg. Record this information.
2. Place an egg in a ziplock bag, squeezing out all of the air in the bag before sealing.
3. Hold a ruler up on the table vertically. Hold the egg vertically at the 2 cm mark. (Keep the excess bag on top.) Drop it. Record your observations.
4. Hold the egg the same exact way at the 4-cm mark and repeat. Continue this process until the egg shell is slightly cracked.
5. Continue until the egg is smashed and the yolk leaks out. Measure the amount of egg still undamaged. How much of the egg is smashed? Be sure to record detailed observations.
6. Fill a bowl with flour and place the bowl inside of the box lid.
7. Measure the length of your egg #2. Measure the mass of your egg. Record this information.
8. Drop the egg from the smash height (Step 5). Measure the amount of egg sticking up out of the rice bed. How much of the egg is buried in the rice? Also, record your observations.
9. Repeat this, increasing the height in 2-cm increments until the egg is cracked, and then smashed.

Data and observations: Add more columns/rows as needed.

Egg #
Drop Height
Cracked or Smashed?
Description and Observations

1
2



1
3



1
6



1
8



1
10



1
12




Calculations: Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.
  • What is the gravitational potential energy in each trial?
  • How much work is done in each trial?
  • How much force was used to stop the egg in each case of steps 5, 8 and 9?

*Read the Physics Talk p279 - 287 before answering the following questions. *
Questions:
  1. This investigate is an analogy for a person in an automobile collision. What does the egg represent? What does the table represent? What does the flour represent?
  2. Define the terms: Kinetic Energy and Work.
  3. What factors determine an object's kinetic energy?
  4. WHen work is done on an object, what is the effect on the object's kinetic energy?
  5. How does the force needed to stop a moving object depend on the distance the force acts?
  6. What difference does a soft landing area make on a passenger during a collision?
  7. How does a cushion reduce the force needed to stop a passenger?
  8. What does the law of conservation of energy have to do with this?


Conclusion:
· Using the law of conservation of energy, explain how an air bag can protect you during an accident. Use specific observations from this investigation to support your answers to these questions.
· Explain at least 1 cause of experimental error. Be sure you describe a specific reason.
· How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?)


USE THE RUBRIC TO MAKE SURE YOU HAVE INCLUDED ALL REQUIREMENTS!


Investigate X6: Momentum and Inelastic Collisions


Objective: What physics principles do the traffic-accident investigators use to "reconstruct" the accident?

Materials: List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).

Procedure:
  1. Place a motion detector at the right end of a track. Open up data studio. Dump "Velocity" into "Graph" display, and enlarge this.
  2. Place a cart on the middle of the track with the velcro to the right. Call this the "target cart." Place a second identical cart on the right end of the track. Call this the "Bullet cart".
  3. Click "Start" on Data Studio, and then push the bullet cart very gently towards the target cart so that they collide and stick together. You may need to practice this a few times. Be sure to get your body out of the way of the motion detector!
  4. Examine the graph produced by the motion detector. Using the Smart Tool, find the velocity right before and right after the collision. Record this in your data table.
  5. Vary the masses of the carts and repeat the process 5 times.

Data and observations: Add more columns/row as needed.
Mass of Bullet Cart (kg)
Mass of Target Cart (kg)
Speed of Bullet Cart (m/s)
Speed of Target cart (m/s)
Combined masses (kg)
Final Velocity of both carts (m/s)





































Calculations: Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.
  1. Find the initial momentum of the bullet cart for each trial.
  2. Find the initial momentum of the target cart for each trial.
  3. Find the sum of the initial momenta of the two carts for each trial.
  4. Find the final momentum of the combined carts for each trial.

*Read the Physics Talk p312 - 315 before answering the following questions. *
Questions:
  1. Compare the initial momenta (calc 3) to the final momentum (calc 4). (Allow for minor variations due to uncertainties of measurement.)
  2. List the 6 types of collisions (top of page 312) and a brief description.
  3. Which types of collisions are definitely inelastic? How do you know?
  4. Which types of collisions are definitely elastic? How do you know?
  5. Define the law of conservation of momentum.
  6. Use the law of conservation of momentum to describe what happens when a cue ball hits the 15 balls in the middle of the pool table.


Conclusion:
· Based on the law of conservation of momentum, how can the traffic-accident investigators use to "reconstruct" the accident? What does it mean to "conserve" momentum?
· Explain at least 1 cause of experimental error. Be sure you describe a specific reason.
· How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?)


USE THE RUBRIC TO MAKE SURE YOU HAVE INCLUDED ALL REQUIREMENTS!